The present invention relates to an electronic still camera which can confirm an image to be formed using a solid-state imaging element before it is formed on a photosensitive film, and then form the image on the film upon operation of a shutter switch.
In recent years, electronic cameras using an image sensor (e.g., a solid-state imaging element) instead of a silver halide (silver chloride) film have been developed, as disclosed in U.S. Pat. No. 4,535,363 or U.K. Patent No. 2,112,603A.
In an electronic still camera of this type, a MOS or CCD (Charge Coupled Device) image sensor is used. Thus, an electronic still camera with 400,000 pixels per frame is commercially available. Although this is suitable for a video camera, where image is watched on a TV screen, if such an image is produced as a hard copy or printed, a clear photograph, like that obtained with a silver-chloride film camera, cannot be obtained.
More specifically, even if the total number of pixels in an image sensor increases up to several tens of times upon innovations in semiconductor design and manufacturing techniques, it cannot reach the 200 to 240 million pixels (silver-halide particles) in the silver-chloride film camera, thus creating a serious problem.
In contrast to this, although the silver-halide film camera can obtain an image of good quality, it must be handled very carefully to maintain the photosensitivity of the silver-chloride film. Since silver-chloride films are expendable, this increases cost. In addition, after an imaging operation, development and printing are needed to confirm an imaged content. Therefore, if erroneously photographed contents are printed, this creates further increase in cost. Even so, a photographed image cannot be confirmed unless the film is developed. For example, when an imaging operation must be successful, an identical object must be imaged a number of times while changing shutter conditions (e.g., aperture, shutter speed, and the like).